Cable sleeve consisting of a covering body and at least one front-face sealing body

ABSTRACT

A cable sleeve includes a covering body having a front-face end defining a circumferential, conically tapered flange. At least one front-face sealing body is positioned adjacent the covering body and has a circumferential, U-shaped sealing groove. A ring seal in inserted into the sealing groove of the sealing body. The ring seal has an L-shaped cross-section and has a first leg that received within the sealing groove of the sealing body and a second leg having a tapered course on both sides broadening towards the first leg. A straining ring fastens the ring seal between the flange of the covering body and the sealing groove of the sealing body.

CROSS-REFERENCES TO RELATED APLICATIONS

This application claims the benefit of foreign priority fromInternational Application No. PCT/DE99/01251, which was published asInternational Publication No. WO 00/30231 in the German language on May25, 2000, and which claims the benefit of foreign priority from GermanPatent Application Serial No. 198 53 203.2 filed Nov. 18, 1998.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cable sleeve comprising a coveringbody and at least one front-face sealing body with a circumferential,U-shaped sealing groove and a ring seal. The covering body comprises atits front-face end a circumferential, conically tapered flange which,together with the ring seal inserted into the sealing groove, is engagedby a straining ring.

2. Description of the Related Art

EP 0 877 716-A2 discloses a cable sleeve which comprises a covering bodycomprising an added flange, to which a sealing system comprising anannular seal is pressed with the help of a straining ring.

EP 0 844 717-A2 discloses a straining ring for flanged joints in cablesets or tubes. The straining ring comprises several partial ringsegments that are engaged by a straining band. During straining of thestraining band, the partial ring segments are radially inwardly pressedonto a sealing system.

WO 96/32660 discloses a hood sleeve formed of a sealing body and a hoodbody. A sealing ring is housed in a sealing groove comprising a variablevolume. As a result of deformation that occurs during closing, thesealing ring is pressed to the inner wall of the hood body by narrowingthe sealing groove, for example with the help of an eccentric.

BRIEF SUMMARY OF THE INVENTION

The problem underlying the present invention is to create a cablesleeve, in which the sealing ratios between the sealing body and thecovering body are improved with the help of a suitable ring seal and astraining ring being adapted thereto. According to the presentinvention, the problem is solved with a cable sleeve of theabove-mentioned type wherein the ring seal comprises as its basiccross-section an L-shape. The cross-section of the first leg of theL-shape is adapted to that of the sealing groove of the sealing body andthe second leg of the L-shape has at both of its sides a taperedcross-section broadening towards the first leg. The tapered course ofthe second leg corresponds at the one side of the course of the taperedflange and at the other side to the course of the conical groove wall ofthe ring groove inside the straining ring. The straining ring comprisesa circumferential projection acting on the first leg of the ring sealpositioned in the sealing groove of the sealing body.

As compared to the known prior art, it is a decisive advantage in thesealing system according to the present invention that the strainingring exerting the sealing pressure not only effects an all-overdeformation of the ring seal, but that, during the closing operation,the sealing towards the covering body is done via the groove wall of thering groove of the straining ring and the sealing towards the sealingbody is done via the action of a circumferential projection on the ringseal. For this reason the ring seal is formed to have an L-shaped basicform, wherein the first leg, which is in general the shorter one, isadapted to the shape of the groove of the sealing body. The second legof the L-shaped ring seal is formed to have a conical shape and servesfor sealing against a circumferential flange of the covering body. Thecircumferential ring groove in the straining ring is formed to have acorresponding conical shape, so that, when the straining ring is closedand its diameter is reduced, the straining ring slides along on theconical counter-surfaces. As a result, an increasing pressure is exertedon the ring seal, wherein the circumferential projection at thestraining ring exerts pressure on the first leg of the ring seal.Further, guiding elements having the shape of a fixing groove and thatof a fixing projection are provided in the straining ring and in thesealing body, respectively, for mutual positioning. The straining ringaccording to the present invention comprises several straining ringparts, and preferably two identical straining ring parts, which arefastened on the sealing region by means of closing elements. The closingelements are preferably threaded bolts or screws arranged in pivotbearings so as to be non-removable and can, after positioning of thestraining ring parts, be threaded into counter-bearings of thecorresponding straining ring part. The straining ring parts are pulledagainst each other by threading the screws of the straining ring andthereby pressing the sealing system together in the above-describedmanner.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention will be illustrated in more detail referring tothe following figures in which like reference letters designate likeparts in the various views and in which:

FIG. 1 shows an assembled cable sleeve according to the presentinvention;

FIG. 2 shows a sealing body according to the present invention;

FIG. 3 shows a ring seal according to the present invention;

FIG. 4 shows a straining ring according to the present invention;

FIG. 5 shows a cross-sectional view of the cable sleeve in the sealingregion before mounting of the straining ring;

FIG. 6 shows a cross-sectional view in the sealing region including anadded straining ring before the sealing system is fully pressedtogether;

FIG. 7 shows a cross-sectional view in the sealing region after thesealing system is fully pressed together; and

FIG. 8 shows a top view of the cable sleeve according to the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a hood sleeve HM in its assembled state. It is obvioustherefrom that the hood sleeve comprises a covering body UK, which is atone frontal side closed to have a hood-like shape. At the opposingfrontal side, the hood sleeve HM is closed by a sealing body, which issealingly inserted towards the covering body UK with the help of asealing system according to the present invention. Besides the ringseal, which is not visible in FIG. 1, a straining ring SR comprising twostraining ring parts SP1 and SP2 is provided for this purpose.Compression of the straining ring SR is achieved with the help ofclosing elements VE1 and VE2 being correspondingly arranged at the endsof the straining ring parts SP1 and SP2. The reduction of the diameterof the straining ring generates the required closing pressure upon thering seal. The hood sleeve HM is further provided with holding bracketsHL, with the help of which a mast fixing is enabled. Further, asuspension device AA is provided for suspending the hood sleeve HM froma carrier cable. Ribs R are provided for increasing the mechanicalstrength and stiffening the covering body UK.

FIG. 2 illustrates a sealing body DK comprising two sealing body partsDK1 and DK2. Cable entrances KE for inserting cables are provided in thesectional plane as well as in the other parts of the sealing body.Non-cut (e.g., express) cables can also be inserted through the cableentrances KE in the sectional plane. The sealing body is provided withcircumferential, U-shaped sealing groove DN, into which a correspondingring seal for sealing against the covering body UK is inserted. Such asealing body DK is in principle known and is already being used forlongitudinally split cable sets, in which a longitudinally split sleevetube is tightly compressed on the sealing body or upon thecircumferential ring seal, respectively. The problem solved by thepresent invention includes among others that such a sealing body canalso be used for a hood-shaped covering body. Since hood sleeves, as aresult of the rigid diameter, do not allow compression, as in alongitudinally split cable set, the sealing system according to thepresent invention has been developed.

FIG. 3 shows the ring seal DR, which has been developed for the newsealing system and whose cross-section comprises an L-shape. Thecross-sectional shape is not clearly visible in this illustration, butthe first leg ES and the second leg ZS of the L-shape are clearly shownin FIGS. 5-7. The first leg ES seats into the sealing groove of thesealing body during assembly, while the second leg ZS seals against thecovering body. Further, a split ring seal DR can be inserted, whereinknown connecting measures are then taken at the separation location TS.

FIG. 4 illustrates the straining ring SR forming, in conjunction withthe previously described ring seal DR, the sealing system according tothe present invention. The straining ring SR in the present casecomprises two identical straining ring parts SP1 and SP2 connected toeach other via closing elements VE1 and VE2.

The closing elements VE1 and VE2 are rotatably arranged in pivotbearings DL1 and DL2, respectively, at the ends of the straining ringpart SP1. After assembly of the straining ring parts SP1 and SP2 to thealready pre-mounted sealing body DK and ring seal DR, the closingelements VE1 and VE2 are with their closing bolts or screws threadedinto counter-bearings GL1 and GL2, respectively, of the correspondingstraining ring part SP2. Finally, by tightening the closing screws, thetwo straining ring parts SP1 and SP2 are pulled together until therequired sealing pressure is applied. The reception profile of thestraining ring SR or of the straining ring parts SP1 and SP2,respectively, is composed of the ring groove RN, a circumferentialprojection DA and a fixing groove FN lying therebelow. When thestraining ring SR or the straining ring parts SP1 and SP2, respectively,are put on, the circumferential flange FL of the covering body UK andthe second leg ZS of the already pre-mounted ring seal DR are insertedinto the ring groove RN. When doing so, the position of the projectionDA for acting upon the first leg ES of the ring seal DR, which hasalready been inserted into the circumferential sealing groove DN of thesealing body, is automatically achieved. What is also automaticallyachieved in this mounting procedure is insertion of the circumferentialfixing projection of the sealing body DK into the fixing groove FN, ifsuch a fixing projection exists on the sealing body.

In the illustrated embodiment, the two closing elements VE1 and VE2 arerotatably arranged in bearings at one straining ring part SP1. Thesecond straining ring part SP2 can thus be moved relative to the firststraining ring part SP1 in the direction of the pivot of the closingelement, depending on how far the two corresponding closing screws S ornuts, respectively, are screwed into or onto, respectively, a thread ofthe closing elements VE1, VE2. Hence, the two straining ring parts SP1and SP2 are at one side not only arranged in bearings to be mutuallyrotatable, but can also be mutually moved in the direction of the pivot.By an alternate tightening of the two closing screws S, the ring seal DRis fastened between the straining ring SR and the hood sleeve HM as wellas between the straining ring SR and the sealing body DK. Fastening ofthe straining ring SR at two sides has the advantage that action of theclosing forces is uniformly distributed over the circumference. Were thestraining ring parts SP1 and SP2 arranged to be only mutually rotatable(and not also mutually movable), no high pre-tightening force would acton the ring seal DR in the region of the pivot. The hood sleeve HM wouldleak first in this region.

FIG. 5 shows the beginning of the assembly for sealing the hood sleeveHM. In this state the ring seal DR is already inserted into the U-shapedsealing groove DN of the sealing body DK comprising two sealing bodyparts DK1 and DK2. In this cross-sectional illustration it can be seenthat the ring seal DR is with its first leg ES seated into the sealinggroove DN of the sealing body DK, while the second leg ZS, in thepresent case the longer leg, is positioned closely to the sealing flangeFL of the covering body UK. As can be seen from the cross-sectional viewof the ring seal DR, both sealing surfaces of the second leg ZS extendtoward the first leg ES in a conically widening manner. Further, it canbe seen that the ring seal DR is provided with several annularlyextending cavities HR to ensure the required flexibility. In addition,it is shown that the conically extending surfaces of the second leg ZSare provided with a wavy structure WS ensuring an improvement of thesealing characteristics. Still further, cable entries KE are shownwherein the middle cable entry is located in the separating area TE ofthe sealing body DK.

FIG. 6 shows the following step of the closing operation. The strainingring SR is already located in its position, so as to encompass with itsfirst flank the flange FL of the covering body UK of the hood sleeve HMand with its second flank the conically extending seal surface of thesecond leg ZS of the ring seal DR. The ring seal DR and the ring grooveRN of the straining ring SR are formed with respect to their crosssection so that the circumferential projection DA is able to act uponthe first leg ES of the ring seal DR being seated into the sealinggroove DN of the sealing body DK. Thus, the first leg ES of the ringseal DR is prestressed between the sealing body DK and the strainingring SR. As can be seen in FIG. 6, the stress direction SP is shown byan arrow in which direction the straining ring SR is moved radiallyduring the subsequent fastening operation.

FIG. 7 shows the final state of the closed sealing system. As can beseen, the sealing is provided between the covering body UK and thesealing body DK at the sealing surface F1 between the flange and thering seal DR and the sealing surface F2 between the ring seal DR and thesecond flank of the straining ring SR. In addition, the first leg ES ofthe ring seal DR is pressed against the sealing surface F3 within thesealing groove DN due to the projection DA of the straining ring SR. InFIG. 7, the angle W at which the sealing surfaces F1 and F2 areinclined, is indicated. This angle also corresponds to the angle openingof the ring groove RN in the straining ring SR, when the outer wall ofthe flange FL extends parallel to the inner wall of the first flank ofthe straining ring SR. Of course, the ring seal DR is formed such thatthe required closing pressure is maintained in the final state. Thematerial of the ring seal is an elastomer, preferably silicone. Tocompensate the process tolerance, the longest possible prestressingpaths of the ring seal DR are utilized. This is primarily achieved byproviding annular cavities HR within the sealing profile. Utilizingcavities HR, prestressing paths can be realized which would not bepossible with massive seals, since silicone materials areincompressible. The cavities HR in the seal are formed such that theremaining webs are not perpendicular to the prestressing direction, andthus, maintain defined deformations during the closing operation. Thewavy structures WS provided on the surfaces F1, F2 and F3 of the ringseal DR create an additional contact pressure. Beside the function ofsealing, the ring seal DR has the additional object to form a flange,onto which the covering body UK can be put while pre-assembling, so thatthe assembling is facilitated due to the geometry of the ring seal. Ascan be further seen in FIG. 7, the outer groove flank of the sealinggroove DN of the sealing body DK forms a fixing projection FA whichseats into a corresponding fixing groove FN of the straining ring SR.Thus, a positioning retention is assured so that the sealing body DKcannot wander off.

FIG. 8 shows in a top view the arrangement of the hood sleeve HM, inwhich the closing means at the right side is already pre-assembled withthe closing element VE2. At the left side, the closing element VE1rotatably mounted in the pivot bearing DL is next pivoted in thedirection of the arrow P into the counter-bearing GL1 of the strainingring part SP2. Subsequently the straining ring parts SP1 and SP2 arepulled against each other by mutual tightening of both screws S untilthe required closing pressure is obtained. Further, holding brackets HLand the suspension projection AA are recognizable.

In summary, known sealing bodies for longitudinally split cable sets maynow be used for hood sleeves with an appropriate ring seal according tothe present invention. In addition to providing a sealing function, thering seal also provides mounting assistance, as the hood sleeve used asa covering body can be placed upon the ring seal which is alreadypositioned in the sealing body. Furthermore, the ring groove of thestraining ring is adapted to the cross section of the ring seal. Thus,an optimal sealing result can be obtained in the prevailing conditions,especially since additional radial contact pressure of the first leg ofthe ring seal in the sealing groove also produces a radial sealingpressure. Because of the annular cavities in the ring seal, there arelarge initial prestressing paths possible. Because of the mechanicalfixation of the sealing body in the straining ring with support of thefixing means, the sealing body is fixed in a way that the initialtension of the ring seal, also at outer mechanical stresses, won't bereduced. According to the illustrated embodiments of the presentinvention, the straining ring parts are not linked together by only oneturning knuckle. Because of the tangential connection with the closingelements, the straining ring parts can be alternately deployed insealing position so that one-sided stress of the ring seal can beexcluded, as it would not be when only one turning knuckle is deployed.Therefore, a steady distribution of pressure is possible during thelocking action.

That which is claimed is:
 1. A cable sleeve comprising: a covering bodyhaving a front face end defining a circumferential, conically taperedflange; at least one front face sealing body positioned adjacent thefront face end of the covering body, the at least one sealing bodyhaving a circumferential groove; a ring seal inserted into the sealinggroove of the sealing body; and a straining ring having a conicallytapered ring groove engaging the flange of the covering body and thering seal; wherein the cross section of the ring seal is substantiallyan L-shape and the ring seal comprising a first leg of the L-shapedadapted to be received within the sealing groove of the at least onesealing body and a second leg of the L-shape having a tapered course onboth sides broadening towards the first leg, the tapered course of thesecond leg corresponding on one side to the conically tapered flange ofthe covering body and on the other side to the conically tapered ringgroove of the straining ring, wherein the ring seal has a Plurality ofsealing surfaces that define an angle equal to the angle between theinner surface of the flange of the covering body opposite the ring sealand the inner surface of the ring groove of the straining ring oppositethe ring seal.
 2. The cable sleeve of claim 1, wherein the strainingring comprises a circumferential projection acting on the first leg ofthe ring seal.
 3. The cable sleeve of claim 1, wherein the ring seal hasat least one annual inner cavity.
 4. The cable sleeve of claim 1,wherein, each of the plurality of sealing surfaces has a circumferentialwavy structure.
 5. The cable sleeve of claim 1, wherein the strainingring is formed from a plurality of straining ring parts that arefastened together by means of closing elements.
 6. The cable sleeve ofclaim 5, wherein the closing elements comprise a first end rotatablyarranged in a pivot bearing provided on at least one of the strainingring parts and a second end opposite the first end that engages acounter-bearing on another of the straining ring parts to fasten thestraining ring parts together.
 7. The cable sleeve of claim 1, whereinthe straining ring has a circumferential fixing groove and the at leastone sealing body comprises a corresponding circumferential fixingprojection that is received within the fixing groove of the strainingring.
 8. The cable sleeve of claim 1, wherein the covering bodycomprises a tube.
 9. The cable sleeve of claim 8, wherein the tube ofthe covering body is longitudinally slit.
 10. The cable sleeve of claim8, wherein the covering body is a sleeve hood having a closed endopposite the front-face end.
 11. The cable sleeve of claim 1, whereinthe covering body comprises at least one suspension projection.
 12. Thecable sleeve of claim 1, wherein the covering body comprises at leastone holding bracket.
 13. The cable sleeve of claim 1, wherein thecovering body comprises ribs for structural reinforcement.
 14. The cablesleeve of claim 1, wherein the ring seal comprises an elastomermaterial.